ATLANTA, Georgia (CNN) -- OutKast's Big Boi is a junkie, has been for years.

Big Boi: "You can really tell a lot about a person through the shoes, so I always like to keep me a fresh pair."

The multiplatinum rap star got his first shoe fix back when he was better known as Antwan Patton, a busboy at Steak and Ale. He saved up his paychecks and rushed to a dealer to cop the only thing that could cure his jones -- a pair of British Knights tennis shoes.

"I've actually been into sneakers since I was a little kid," Big Boi, 34, said backstage before his concert this month at the Sneaker Pimps exhibition in Atlanta. "You can really tell a lot about a person through the shoes, so I always like to keep me a fresh pair."

Sneaker culture has thrived for decades, but shoe companies have increasingly capitalized on the demand for one-of-a-kind kicks. Collectors, known as sneakerheads, have lined up to pay hundreds, even thousands, of dollars to ensure few people are wearing the same shoes. See some of the rarest shoes »

"Coming up, my mom got five kids so there wasn't a whole lot of stylish tennis shoes around the house, so I used to want a lot of sneakers," Big Boi said, explaining that he started making up for lost time -- and shoes -- long before OutKast's 1994 debut, "Southernplayalisticadillacmuzik."

Juan Castaneda, 27, also grew up in a family of modest means and longed to don the fresh kicks he saw his peers wearing.

"When I got money to buy them, I started catching up," said Castaneda, who works at a nursing home in Hendersonville, North Carolina.

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He estimates he owns about 200 pairs of sneakers, including a pair of Nike Air Jordan XIs with patent-leather trim called "Space Jams." They cost him $500.

It's supply and demand at its simplest, said Elliott Curtis, a former Carnegie Mellon University basketball player who for two semesters taught Sneakerology 101, billed as the first accredited class on sneaker culture.

Shoe companies create a limited number (say, a few hundred pairs) of shoes -- even if it's just an old model with new colors or materials -- and demand automatically spikes.

"It's like a status symbol. If Nike is selling a shoe for $2,000, they're not expecting to sell that many," the recent graduate said, adding that sneakerheads are drawn to scarcity.

"If they've got money, they can buy coolness," Curtis said.

Curtis goes to garage sales and mom-and-pop stores seeking rare and retro sneakers for his 75-pair collection, but he concedes he's waited in line for limited editions and paid as much as $250 for a pair.

Sporting an ultra-rare set of blue-and-red "Bugs Bunny" Nike Air Jordan VIIIs, Big Boi said he today boasts at least 400 pairs of sneakers, but he rarely pays for them because shoe companies send him pairs.

His most expensive, a pair of crocodile-skin Nike Air Force 1s, sell on various auction sites for up to $1,800. Big Boi has never worn them, but he plans on taking them out of their Nike lockbox this summer so he can wear them in a video for his upcoming solo album.

Sneaker culture got its start in New York in the 1970s, mostly among playground streetballers and practitioners of an emerging genre of music called hip-hop. Over the next three decades, rappers and basketball players -- most notably, Run DMC and Chicago Bulls legend Michael Jordan -- would play integral roles in boosting the popularity of rare kicks.

"Run DMC were probably at the height of the whole movement. It was the first time music and sneakers crossed like this," Fahey said of the group's 1986 hit, "My Adidas."

Today, Adidas, Nike and Puma compete with luxury brands such as Chanel, Prada and Gucci. The major sports shoe companies also allow customers to design their own shoes. Upstarts such as San Francisco's JB Classics and Japan's Madfoot and KKOK have snatched up market share as well.

Shoe companies realize hip-hop's influence and work hard to get "a fresh pair of steps" on a rapper's feet. Earlier this year, Converse released a line of its iconic All-Stars in tandem with Chicago rhymesmith Lupe Fiasco. Nike has issued two versions of the Air Yeezy, inspired by rapper-producer Kanye West. Louis Vuitton also has teamed up with West.

Some lines, such as the Yeezys, quickly become collectors' items. Die-hard sneakerheads keep them in their original boxes like "Star Wars" action figures and ferret them away in closets, their soles never to be scuffed by a sidewalk.

Bryan Lyle, 22, of Stockbridge, Georgia, said he recently camped out three nights at an Atlanta boutique to get one of the shop's eight pairs of Air Yeezys.

Lyle paid $300, a small fortune for shoes, but Castaneda said the price more than doubled within days. He got a pair of Yeezys from an eBay merchant in Hong Kong. The damage? $700.

Melissa Bailey of Hendersonville, North Carolina, takes photos at the Sneaker Pimps show.

Castaneda's girlfriend, Melissa Bailey, 26, said Castaneda actually bought three pairs. He found two online and paid someone to camp out for the others. Castaneda's modus operandi is to buy three pairs of his favorite shoes -- one to wear, one to store for later and one to sell or trade, she said.

"He will not walk through grass. He will not walk through dirt," Bailey said.

For the last six years, Fahey has had a front-row seat for the evolution of sneaker culture. He held the first Sneaker Pimps show in Sydney, Australia, in 2003, but only 200 people showed up, belying the trend's rising popularity.

Soon, however, tens of thousands would attend shows in more than 60 cities. A 2006 show in Jakarta, Indonesia, drew about 13,000 sneakerheads.

The shows now feature between 1,000 and 1,500 shoes. Some are rare. Others are signed by celebrities. Hip-hop acts are a staple, as is artwork -- on both kicks and canvas.

At this month's show, hundreds of sneaker enthusiasts filed through Atlanta's Tabernacle with the decorum of museum patrons, stopping to admire the shoes displayed on swaths of chain-link fence.

There were novice sneakerheads, such as Chris Shepherd, 20, and Charnelle Cook, 20, an Atlanta couple who marveled over the DC Comics and Transformers sneakers.

Asked about her multicolored hightops, Cook said, "I couldn't tell you what these are called. All I know is they're Reeboks, and they're fly."

There were seasoned collectors, such as Kyle Self, 35, of Decatur, Georgia, who said he had about 25 pairs, some of them still in their boxes. Included in the group are three pairs of $400 low-top Pradas, which he called his "everyday sneakers."

There were even female collectors, such as artist Estasha Goodwin, 23, who modeled a pair of shimmering gold, winged -- yes, winged -- hightops made by Adidas and designer Jeremy Scott.

She complained that shoe companies too often focus on the male market and ignored female aficionados.

"When they do cater to us, it's always bubblegum pink. They don't even make them in our sizes," she said. "I know women who know more about sneakers than any dude out here today."

Incidentally, her favorite of the 15 pairs she owns were made for men -- the Nike "Ace of Spades" Dunks, inspired by the Detroit Tigers' high-kicking pitcher, Dontrelle Willis, who is prominently featured on the black-and-aqua shoe's hightop.

Asked why she shelled out $250 for them, she gave a familiar response: "It's a feeling you get when you know you're the only one that has something. Even if you're not, it's the way you walk it."